Vascular graft infection by Staphylococcus epidermidis: efficacy of various perioperative prophylaxis protocols in an animal model

A rat model was used to investigate the efficacy of levofloxacin, cefazolin and teicoplanin in the prevention of vascular prosthetic graft infection. Graft infections were established in the subcutaneous tissue of 300 male Wistar rats by implantation of Dacron prostheses followed by topical inoculation with methicillin-susceptible and methicillin-resistant S. epidermidis. The study included a group without contamination, two contaminated groups without prophylaxis, two contaminated groups with intraperitoneal levofloxacin prophylaxis (10 mg/kg), two contaminated groups with intraperitoneal cefazolin prophylaxis (30 mg/kg), two contaminated groups with intraperitoneal teicoplanin prophylaxis (10 mg/kg) and six contaminated groups with rifampin-soaked graft and intraperitoneal levofloxacin, cefazolin or te- icoplanin prophylaxis. The grafts were removed after 7 days and evaluated by quantitative culture. The efficacy of levofloxacin against the methicillin- susceptible strain did not differ from that of cefazolin or teicoplanin. Levofloxacin showed slight less efficacy than teicoplanin against the methicillin-resistant strain. The levofloxacin-rifampin combination proved to be similarly effective to the rifampin-teicoplanin combination and more effective than the rifampin-cefazolin combination against both strains. The rifampin-levofloxacin combination may be useful for the prevention of late-appearing vascular graft infections caused by S. epidermidis because it takes advantage of the good anti-staphylococcal activity of both drugs.